This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a multi-center, doubl-arm,blinded, placebo controlled, randomized (2:1 ratio of study drug to placebo), phase II clinical trial of Thymoglobulin (Antithymocyte Globulin) for use in the treatment of new oneset type 1 diabetes mellitus (T1DM) subjects, aged 12 to 35 years.